My COE bed sat outside from April-Nov for three years since painting the ~19 ft boards in 2012. I have not seen and color changes and no splitting/checking of the boards (only painted on the exposed up-side surfaces).
To help prevent checking/splitting on the undersides of the boards, we sprayed the underneath with 2 coats of POR-15 a year after the top of the boards were painted using the Mar-K-method.
Here are some photos and text of the painting steps, that I posted on the oldGMCtrucks.com forum after the painting day:
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2 July 2012
oldGMCtrucks.com Discussion Boards
54/55 350 COE bed paintedIt's been five years since I obtained this
Z-Series 2-ton COE that Grigg Mullen dragged (flat-towed) from WA state to NY (by way of Macungie, PA).
The front and rear wheel bearings are all new; all brake parts (pads, wheel/main cylinders, and hydrovac) are new, except for the lines; and, the engine now runs fine.
The main electrical/mechanical things that need to be attended-to is the SM-420 transmission needs to have the front cover replaced (easy) and the front tires look a little rough/old. All electrical wiring will be replaced but I have not decided if it will be 6v positive ground or 12v negative ground.
All sheet metal has been stripped, repaired and primed. All sheet metal should get finish painted this summer (Red body and White grill; and, standard two slightly metallic brown interior colors). This will look like a work truck.
For about 5 years, the COE has been in a large truck storage garage at my friend Dave's grandfather's house about 15 miles away. The drive train and bed are still on the chassis but everything else has been removed.
On Sat/Sun, we brush-and-roller painted the weather-worn non-GM flat/stake bed (that had never been painted/preserved).
http://1954advance-design.com/Web%20images/COE-Photos/bed-paint/1-before-bk.jpgThe above BEFORE photo is from the rear of the 8' wide by 18' long bed. All boards, except for the right-most board, are tongue and groove. Dave torch-cut off the forward head-board "cage" and the rear "bumper". We will custom make replacements.
We cleaned off splintered wood and cleaned out all grooves between boards.
Dave and I were dressed in our Sunday best, throw-away, painting gear, with almost all of our bodies covered from toe-to-neck (even though 90+ degree weather was expected). Notice the duct-taped rip-repair on my paints, and plastic gloves going over flannel-shirt long-sleeve ends.
http://1954advance-design.com/Web%20images/COE-Photos/bed-paint/2-before-fr.jpgHere is what we used as paint:
Coat 1 - POR-15 semi-gloss
Rust Preventative Paint (wait 2-3 hours for firm tacky surface)
Coat 2 - POR-15 semi-gloss Rust Preventative Paint (wait 2-3 hours for firm tacky surface)
Coat 3 - POR-15 Chassis Coat Black (let set overnight)
Coat 4 -
BEHR PREMIUM PLUS ULTRA Exterior Semi-Gloss Enamel
Process:
1. Prior to rolling-on the first coat, we "cut-in" with brushes between each board (to get to the now-exposed-by-weathering tongue-and-groove "openings"/separations).
2. Apply with rollers the first three coats (liberal application, rolling about three feet front-to-back, side-to-side, and again front-to-back.
3. Before applying the 4th/final coat, "cut-in" with brushes between each board and then apply with rollers.
We applied coats outside until about 9am each morning. Other coats were applied inside of a large truck garage (30 ft ceilings) with the front door/wall opened.
The final result is not a show-quality finish, but the surface is thoroughly covered and sealed. It does not look too bad/good - but, who cares.
http://1954advance-design.com/Web%20images/COE-Photos/bed-paint/3-bed-bk-4th-coat.jpgThe AFTER photo above is from the rear (the blanket-cover on the front is over the front-frame/engine/transmission)
The AFTER photo below is from the front. Note the "daylight" between the left two boards - that last board on each side was not tongue-and-grooved.
http://1954advance-design.com/Web%20images/COE-Photos/bed-paint/4-bed-fr-4th-coat.jpgWe (meaning, Dave) will fabricate a metal front-end bed-edge cover and headboard. And, we/Dave will fabricate a rear-cover/bumper, light-license bar/holder.
The deck is about 50" off the ground. I will obtain an aluminum ramp system for loading and unloading my 1/2 ton trucks. The ramps and stands will be stored under the bed (no piece weighs more than 50 lbs)
This is the biggest toy I have ever owned. I probably should not have undertaken this project; but, so it goes.
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http://www.mar-k.com/wood_finish_testing_ii.aspx======================================
Z-series GMC 350 COE
1954 Chevrolet 3106 & 3104
